Remote keyless entry (RKE) systems and tire pressure monitoring (TPM) systems are commonly installed on vehicles. The RKE and TPM systems include a transmitter, which transmits encoded signals or commands that are received by a receiver within the vehicle. As such, the vehicle receiver is configured to decode the receive signals and provide the decoded signal to a microprocessor within the vehicle for execution of the commands.
The encoded signals generated by the transmitter are conventionally in binary form. For example, the transmitted signal includes a digital data stream of logic one and logic zero bits. With the conventional systems, the criteria for determining whether a bit within the transmitted signal is a logic one or a logic zero is via a fixed threshold. Although the conventional RKE and TPM systems are configured to receive and decode the transmitted signal, there exists a wide horizon for improvement.
It is well known that under certain conditions, when utilizing the fixed threshold, the transmitted logic bits may be incorrectly interpreted by the receiver. For example, certain weather or atmospheric conditions cause the signal strength of the transmitted signal to be compromised which affects the interpretation of the transmitted signal. Thus, it is possible for a logic one bit to be interpreted as a logic zero bit and a logic zero bit to be interpreted as a logic one bit, thereby causing undesired performance of the RKE and TPM system.
The present invention was conceived in view of these and other disadvantages of conventional decoding strategies for RKE and TPM system signals.